Process for the manufacture of artificial porphyry or artificial granite and the product thereof



l at ented Oct. 1 '1 I 1.1 2,572,

PROCESS FOR THE MANUFACTURE OF ARTIFICIAL PORPHYRY OR ARTIFI- CIAL GRANITE AND THE PRODUCT T EREOF Ivan Orsini, Cairo, Egypt No Drawing. Application January 21, 1948, Serial No. 3,548. In Great Britain March 7, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires March 7 1 964 3 llaims. (01. 25-155) This invention relates to the pr du t n. of tiles or moulded blocks consisting oi a cementitious aggre ate havin the appearan and properties of porphyry or artificial g anit compact finely ground limestone, this mixture According to the invention, oementitious 5 being shifted through a screen of at least 900 granules, of at least two difierent colours are I meshes to the sq. cm. The sifted powders are separately prepared, mixed together without then mixed with from 30 to 40 per cent. of their crushing the granules, and. moulded cold under volumeof water with the object of making the pressure, th uld d prqdqctg being allowed capillary cohesion of the particles as close as to harden after removal from the mould, possible, and thus giving a perfectly uniform The granules of each colour are preferably paste. In this way lumps are formed, which made from a, mixture of Portland cement or are exposed to the air on a clean surface in order whit cement, or both, with powdered white to eliminate the superfluous water contained in marble or a coloured nlling powder, or both, them. About one-third of the water is lost after with or without an admixture of; o her fil n 40 minutes drying- The l mps of moist pas e powdersor mortar are then forced through a steel-wire The object 01' the invention is to produce arscreen having square meshes measuring from tificially. inexpensively and without heating, a 4 to 8 millimetres between'the axes of the wires. material resembling natural porphyry as closely The amount of moisture in this mortar must as Possible, both in appearance and in its physbe a maximum, but it must at the same time 'ical, chemical and mechanical properties, This enable it to pass through the mesh. In this material may serve numerous purposes, but is way small grains of grey mortar are obtained, more particularly intended for use in the form of a diameter proportionate to the Size of the of pavin and wall-facing tiles, decorative lining mesh. panel for building purposes, etc. excellent re- Parallel to this operation, white grains are presults being obtained owing to its great resistance pared by the same process, but using good hyto wear, shock and absorption, to its very great draulic lime (known commercially as white variety of shades, and to its brilli nt appearance. cement) in the place of the Portland cement, Thanks to its cheapness, therefore, it maybe the same amount of water being employed. substituted for vitrified ceramic tiles, or for nat- The grey and white granules are then ural marble, prophyry or granite lining blocks. thoroughly mixed in a proportion varying ac- This material consists of a cement mortar and cording to the shade eventually required, care a filling powder. This filling powder has the being taken to keep the grains whole. This following properties: homogeneous mottled moist mortar mixture is (1) It increases the power of cohesion; then moulded in steel moulds and compressed (2) It in rea es the jmperviousness of the under a minimum pressure of 250 kg. per sq. cm., mortar after hardening; .for example, in the case of paving tiles.

(3) It reduces its liability to expansion and The chemical action of the cement (the atnt a ti and tack on the silica by the lime) starts immediate- (4) Some filling powders, such as powdered 40 1y on the mixture with water. As, however, the clay brick, kaolin powder or finely ground porspongy grains are sent into the mould and subcelain rubble, protect the cement against attack jected to high pressure before entirely losing b id their water, the material loses nothing of its Two classes of filling powder are to be disl resistance Concrete, n pr pared at tinguished: works on a large scale, takes sometimes over half A. Active powders, which give at least some an hour to reach the shutterings from the mixer, industrial advantages to the manufacture of the nevertheless it loses nothing of its resistance. material, for instance by diiiusing the colour After being removed from the moulds the tiles xid or absorbing expansions without affecting are kept for several days for hardening in a room the final strength of the product: coarse grains shaded from bright light and draughts, in pools of quartz sand or sillcious sand. crushed terra A of water at a temperature not lower than 25 cotta, powder of compact silicious limestone: and centigrade.

B. Powders with disintegrating properties: There then g n the procgss of. flitting, fine raw sand, sodium chloride, earths produced which consists in the removal of a thin layer from the rubble o! brickyards, etc. 86 from the upper surface of the tile, varying between 0.4 and 1 mm., consisting of 3 separate layers:

(a) The stratum of lime, silica, .etc. brought to the surface by the hardening of the mortar; (b) The stratum of foreign dust adhering toit;

(c) The stratum of fine powder formed from the attrition of the granules deposited at the bottom of the mould.

The tiles are finally polished by machinery before being put on the market. Apart from their greater brilliancy they resemble grey ceramic tiles, particularly as regards their edges, which are as sharp as porcelain.

This process renders it possible to imitate artificially porphyry or granite of all shades and varieties. All that is required is to mix coloured oxides (off iron, chromium, etc.) in certain proportions with Portland cement or white cement simultaneously with the 'mixing of the cement with the filling powder. In this way a very great variety of textures of the grains is obtained, according to the proportionate blending of the various mortars, their composition, and the size of mesh of the screens used. Portland cement and white cement mixed with metallic oxides for colouring maybe replaced by the coloured cements normally on the market for some years past. I give below, by way of example, the proportions of the mixtures for the production of various colours and forms of granulation. These proportions may be'taken to be by volume. though since they are obviously only approximate, and the substances employed are all of about the same specific gravity, the same proportions by weight would yield similar results.

Light grey 1 volume (grey granules) 3 parts of Portland cement 2 parts of compact grey limestone powde Against 2 volumes (white granules) 1 part of white cement 1 part of Portland cement 1 part of powdered white marble Pale yellow 2 volumes (yellow granules) 1 part of Portland cement 1 part of white cement 1 part of powdered white marble 12 of powdered yellow iron oxide Against 1 volume (white granules) 2 parts of white cement 1 part of powdered white marble Grey-red 2 volumes (red granules) 2 parts of Portland cement 1 part of crushed terra cotta 8 of red iron oxide Against 3 volumes (grey granules) 2 parts of Portland cement 3 parts of powdered white marble White-yellow-green 4 And against 1 volume (white granules) 2 parts of white cement 1 part of powdered white marble. j

It is to be understood that these cements and powders undergo the same cycle of operations as has been described above for the manufacture of grey porphyry, as regards the sifting through a sieve of 900 meshes per sq. cm.: kneading with water, the preparation of the granules etc.: and these combinations of shades can be multiplied indefinitely.

This material i very compact, and its specific gravity is 2.2.

I claim:

1. The process of forming an artificial tile having the mottled appearance and substantially equivalent physical characteristics of artificial granite, porphyry and the like comprising hydrating a finely powdered mass of white hydraulic lime intimately mixed with an inert filler powder with an excess of water, separately hydrating a finely powdered contrastingly colored Portland cement homogeneously mixed with a filler powder with an excess of water to separately form pastes of both cementitious bodies, allowing said pastes to partially hydrate with a substantial portion of the water whereby the pastes are reduced to a slightly moist condition, separately breaking the stiffened pastes into lumps and separately ex-' truding said lumps through screens to form granules 4-8 mm. in diameter to separately produce homogeneous but contrastingly colored granular bodies, then mixing said separate granular bodies to homogeneously desirable contrast-- ingly colored granules into a single mottled appearing moist cementitious mass without abrasively destroying the granular character thereof,- pressing the granular mix in a mold at a pressure exceeding 250 kg. per sq. cm. to produce a finely set and non-porous cementitious molding, withdrawing the molded product from the mold and aging the same in water to complete the hydration and age the same to ultimate hardness and finely grinding and polishing at least one surface of said molded cementitious product to develop the mottled natural stone appearance.

2. Artificial molded and hydrated cementitious product having the high physical strength and mottled appearance of natural granite, porphyry and the like, consisting of a hydraulically set coherent mass comprising homogeneous granules of hydraulic lime and homogeneous granules of contrastingly colored Portland cement.

3. Cementitious product as defined in claim 2, wherein the contrasting color is obtained by a finely powdered colored mineral filler homogeneously embedded in one of the powdered cements prior to hydration.

IVAN ORSINI.

REFERENCES CITED The following references are of record in the file of this patent:

Great Britain "u-" Aug. 18, 1903 s 

